1. Field of the Invention
The present invention relates to an imprint apparatus, detection method, article manufacturing method, and foreign particle detection apparatus.
2. Description of the Related Art
An exposure apparatus generally has no function of detecting foreign particles existing on a substrate such as a wafer. This is so because an exposure apparatus uses an optical transfer technique, so even if a foreign particle exists on a substrate, only a shot region where the foreign particle exists becomes defective, and there is no influence on other regions where no foreign particle exists. However, a technique of detecting foreign particles existing on a substrate before it is loaded into an exposure apparatus, that is, detecting foreign particles existing on a substrate outside an exposure apparatus is known. On the other hand, if a foreign particle exists on a reticle (mask), all shot regions on a substrate onto which a pattern of the reticle is to be transferred is affected (that is, all the shot regions become defective). Accordingly, an exposure apparatus has a function of detecting foreign particles existing on a reticle (or pellicle) (see Japanese Patent Laid-Open No. 7-43312).
Also, an imprint apparatus has recently attracted attention as a lithography apparatus using the imprint technique. The imprint apparatus cures a resin on a substrate while pressing a template (mold) having fine patterns against the resin, and transfers the patterns onto the substrate by removing the mold from the cured resin.
In this imprint apparatus, however, if a foreign particle exists on a substrate, the foreign particle is sandwiched between the mold and the substrate when the mold is pressed against the substrate, and this may break the patterns of the mold. To prevent this, it is possible to detect foreign particles existing on a substrate outside the imprint apparatus by using the above-described technique, and load the substrate from which the foreign particles are removed in accordance with the detection results into the imprint apparatus. In this case, however, a foreign particle may adhere on the substrate while it is loaded into the imprint apparatus.